Foreground ray-screen.



UNITED STATES PATENT OFFICE.

Jona a nomaaoox, or NEWARK, New sanear, assigner, ro es oaea incarna,me.,

0F NEW 'YOBL 1N. Y.

roaaenounn aar-scarsi?.

Specification of Letters ratei-it.

Patented Apr. 4, 1911.`

To all whom it may commi:

Be it known that I, JHN K. Houmoox, a citizen of the United Stateand aresident of Newark, in the county of ssex and State of New Jersey, haveinvented a new and Improved Foreground Bay-Screen, of which thefollowing is a full, clear, and exact descri tion.

is invention relates to a foreground ray screen for cameras or otherpieturestaking devices.

It is a well known factlthat in taking )lioto hs of landsca on a brightsunny i ny, t e right blue o the sky -affects the .sensitive plate orfilm ten or more times as quickly as the grass and trees, so that gen'orally an overexposed picture of the clouds is necessary, to obtain ooddetail of the grass and trees, or, on t e other hand, the under-exposureof the grass and trees is necessary, in order to obtain a detailexposure of the clouds and sky.

An object, therefore, of this invention is to provide a. device whichwill retard those rays which Aact on the sensitized'plate or filmqiiickt, and thereby obtain a photograph in vhich the detail throughoutwill be just rig it.

A further object of this invention is to provide a device which will besimple in construction inexpensive to manufacture, strong, durable, andreadily adjusted.

These and further objects, together with the construction andcombination of parts will be more full described hereinafter anparticularly set orth in the claims.

Reference is to be had to the accomparing drawin formin a part of thisspec cation, in w ich s ar characters. of reference indicatecorresponding parts in all the views, and in which- Fi re 1 is a frontview in elevation of one crm; Fig. 2 is a vertical section through thescreening member of either form; Fig. 8 is a front view in elevation,partly in'section, of another form; and Fi 4 is a vertical sectionthrough the form ilustrated in Fig. 3.

Referrin more particularly to' the separate arts, represents a holder ofany form suita le to t over the end of thelens hood of a camera, and maybe removably secured thereto by a plurality of inwardl extending springrips 2 provided with ru ber covers 8. The holder isprovided, in bothforms, with a filter or screening member 4, which lby a layer or in thecase of the form illustrated in Fig. 1 is immovable and preferabl of acircular shape. In both forms, the ii tering member 4 consists, as willbe more clearly seen by reference to Fi 2,'of a pair of sheets 5 and 6of any suitab e transparent material, such as glass, havin parallelfaces spaced apart 1m of colloidal material 7, such as cement, saidlayer of cement con taining a coloring matter of a yellowish or 'ambertint.

It willbe noted that the layer 7 is'wedgeshaped, being thickest at thetop and tapering gradua y downward to microscopic thinness at t ebottom'. The difference in thickness of this colored cement issiifiicient to give a screen of the required colored density at the topand of the required clearness at the bottom, with a gradual variationbetween the top and the bottom. The thick-.

ness however, of the cement layer, even at its thickest point at the topis about eight to ten thousandths of an inch, so that this wedge shape,while giving the desired color variation, does not produce anyundesirable prismatic eii'ect.

In the case of the form shown in Fig. 3, the variation in color effectis spread out over a distance considerably dimensions of the lens towhich the device is applied and the screening member is made aJustable', so that any portion thereof can be brought into 'coperativerelation with the lens, thus adaptin the device to be adjusted tovarious con itions where rester or lessscreenin etlect is desired. orthis purpo the ho der 1 is extended on either side, an is provided withbent-over fianes 8, which form ways between which t e screening member 4is ada ted to slide. The ways themselves may suiiiciently tight to holdthe screening member in any a justed position, or an auxiliary spring 9,concealed within one of ,the ways, may-be provided for this purpose.

While- I have shown two embodiments of my invention, I do not wish to belimited to the specific details thereof, but desire to be protected invarious changes', modifications and alterations which I may make withinthe scope of the a pended claims.

Having thus escribed` my invention, I claim as new and desire to sedareby Letters Patent:

1. A ray screen for a camera, adapted to ater than the modify the action.of the light comin therethrough, comprisin a plurality of s eets oftransparent materia and a layer of cement interposed between said sheetsand adapted to secure said' sheets together, said layer taperinggradually. from one edge of the sheets to t e opposite edge.

2. A ray screen for a camera, adapted to modify the action of the lightcomin therethrough, comprisin a plurality of s eets oftransparentmateria and a layer of cement interposed between said sheetsand adapted to secure said sheets together, said layer ta ring(gradually from one side to the ol er, an having a ray-filteringcoloring t ierein.

20 transparent material, and a ayer of colessmo y loidal materialinterposed between said sheets, said layer tapering gradually from oneside to the other.

4. A ray screen for -a camera, adapted to modify the action of the lightcomin therethrough, comprising a. plurality of s eets of ltriis arentmaterial, a'nd a ayer of co1- o ia sheets, said layer tapering graduallyfrom one side to the other and having a ray-filtering coloring, wherebycertain rays of light have their rate of travel changed in passing.through the screen.

In testimony Vwhereof I ha've signed my material interposed betweensaid' name to this specification in the presence of 35 two subscribingwitnesses.

JOHN K. HOLBROOK. Witnesses:

F. W. HANAFonD, PHILIP D. RoLLHAUs.

